A hybrid vehicle may be propelled by an engine and an electric machine. In some examples, such a hybrid vehicle may include a dual clutch transmission. Typically, such a dual clutch transmission may include a park gear, and a parking pawl. The parking pawl may engage the park gear, to prevent an output shaft of the transmission from rotating. Such a function may be achieved via a cable, hydraulic piston, or a motor. However, such a parking pawl increases weight and adds componentry to the vehicle. Such componentry may be susceptible to degradation, which may lead to customer dissatisfaction. The inventors herein have recognized these issues.
Accordingly, the inventors herein have developed systems and method to address the above-mentioned issues. In one example, a method comprises in response to a first condition, engaging a first gear and engaging a second gear of a dual clutch transmission in response to a request to enter a vehicle park state where an output of a transmission is held from rotating, the first gear coupled to a first layshaft, the second gear coupled to a second layshaft; and in response to a second condition, engaging a third gear and engaging a fourth gear of a dual clutch transmission in response to a request to enter a vehicle park state where an output of a transmission is held from rotating, the third gear coupled to a first layshaft, the fourth gear coupled to a second layshaft.
In one example, the first and second conditions are first and second road grades. In another example, the first and second conditions are first and second vehicle conditions (e.g., an indication of degraded gears and no indication of degraded gears).
In this way, the first gear and second gear, or third gear and fourth gear, may be used to tie up the transmission where the transmission includes a dual clutch transmission. By tying up the transmission, the output shaft may be held from rotating in the absence of a park pawl mechanism By avoiding including the park pawl in the vehicle, weight attributed to the park pawl and associated componentry may be avoided, and costs improved, which may result in increased customer satisfaction. Furthermore, by avoiding the use of the park pawl, degradation associated with the park pawl and its associated componentry may be avoided.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.